public class Student extends Person {
    private String className;
    
    public Student(String id, String name, String className) {
        super(id, name);
        this.className = className;
    }
    
    @Override
    public void displayInfo() {
        System.out.println("学号：" + id + "，姓名：" + name + "，班级：" + className);
    }
    
    public String getClassName() { return className; }
}